12 research outputs found

    Augmented antitumor activity of 5‐fluorouracil by double knockdown of MDM4 and MDM2 in colon and gastric cancer cells

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    Inactivation of the TP53 tumor suppressor gene is essential during cancer development and progression. Mutations of TP53 are often missense and occur in various human cancers. In some fraction of wild‐type (wt) TP53 tumors, p53 is inactivated by upregulated murine double minute homolog 2 (MDM2) and MDM4. We previously reported that simultaneous knockdown of MDM4 and MDM2 using synthetic DNA‐modified siRNAs revived p53 activity and synergistically inhibited in vitro cell growth in cancer cells with wt TP53 and high MDM4 expression (wtTP53/highMDM4). In the present study, MDM4/MDM2 double knockdown with the siRNAs enhanced 5‐fluorouracil (5‐FU)‐induced p53 activation, arrested the cell cycle at G1 phase, and potentiated the antitumor effect of 5‐FU in wtTP53/highMDM4 human colon (HCT116 and LoVo) and gastric (SNU‐1 and NUGC‐4) cancer cells. Exposure to 5‐FU alone induced MDM2 as well as p21 and PUMA by p53 activation. As p53‐MDM2 forms a negative feedback loop, enhancement of the antitumor effect of 5‐FU by MDM4/MDM2 double knockdown could be attributed to blocking of the feedback mechanism in addition to direct suppression of these p53 antagonists. Intratumor injection of the MDM4/MDM2 siRNAs suppressed in vivo tumor growth and boosted the antitumor effect of 5‐FU in an athymic mouse xenograft model using HCT116 cells. These results suggest that a combination of MDM4/MDM2 knockdown and conventional cytotoxic drugs could be a promising treatment strategy for wtTP53/highMDM4 gastrointestinal cancers

    Correlations of survival with progression-free survival, response rate, and disease control rate in advanced biliary tract cancer: a meta-analysis of randomised trials of first-line chemotherapy

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    Background: The need to promote novel drug development for advanced biliary tract cancer (ABTC) has emphasised the importance of determining whether various efficacy end points can act as surrogates for overall survival (OS).Methods: We conducted a literature search of randomised trials of first-line chemotherapy for ABTC and investigated correlations between efficacy end points and OS using weighted linear regression analysis. The ratios of the median OS, median progression-free survival (PFS), response rate, and disease control rate in each trial were used to summarise treatment effects. The surrogate threshold effect (STE), which was the minimum treatment effect on PFS required to predict a non-zero treatment effect on OS, was calculated.Results: Seventeen randomised trials with 36 treatment arms were identified, and a sample size of 2148 patients with 19 paired arms was analysed. The strongest correlation between all evaluated efficacy end points was observed between median OS and median PFS ratios (r2=0.66). In trials with gemcitabine-containing therapies and targeted agents, the r2-values were 0.78. The STE was estimated at 0.83 for all trials and 0.81 for trials with gemcitabine-containing therapies, and was not calculated for trials with targeted agents.Conclusions: The median PFS ratio correlated well with the median OS ratio, and may be useful for planning a clinical trial for novel drug development

    Successful Treatment with Modified FOLFOX6 and Panitumumab in a Cecal Cancer Patient Undergoing Hemodialysis

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    Combination chemotherapy of mFOLFOX6 (5-fluorouracil, leucovorin, and oxaliplatin) plus panitumumab, a fully human monoclonal antibody against epidermal growth factor receptor (EGFR), is one of the standard treatments for metastatic colorectal cancer (mCRC) without KRAS mutation. A few reports suggested no need of dose adjustment of cetuximab, a similar chimeric anti-EGFR antibody, in patients with renal impairment. However, panitumumab combined with cytotoxic drugs for hemodialysis patients has not been reported. We herein report a case of a hemodialysis mCRC patient successfully treated with mFOLFOX6 and panitumumab combination therapy

    Successful Treatment with Modified FOLFOX6 and Panitumumab in a Cecal Cancer Patient Undergoing Hemodialysis

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    Combination chemotherapy of mFOLFOX6 (5-fluorouracil, leucovorin, and oxaliplatin) plus panitumumab, a fully human monoclonal antibody against epidermal growth factor receptor (EGFR), is one of the standard treatments for metastatic colorectal cancer (mCRC) without KRAS mutation. A few reports suggested no need of dose adjustment of cetuximab, a similar chimeric anti-EGFR antibody, in patients with renal impairment. However, panitumumab combined with cytotoxic drugs for hemodialysis patients has not been reported. We herein report a case of a hemodialysis mCRC patient successfully treated with mFOLFOX6 and panitumumab combination therapy
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